March 28, 2007 12:00 AM - Lisa Von Ahn, Reuters

There's an old joke about the number of people it takes to change a light bulb. But because the newer energy-efficient kinds contain tiny amounts of mercury, the hard part is getting rid of them when they burn out.

March 27, 2007 12:00 AM - Jon Hurdle, Reuters

A pair of bald eagles, a species that has recovered from the brink of extinction in the last 40 years, has built a nest in a former Navy yard on the south side of Philadelphia, the sixth-largest U.S. city and where the Declaration of Independence and Constitution were written.